Opportunistic vegetation in quarry soil restoration from semiarid South
East Spain: pines and spontaneous species.
Abstract
The objective was to know the effect of amendments and mulch (pine
woodchips) on three planted autochthonous species in two substrates six
years after the beginning of the restoration. But because this kind of
mulch contained pine cones, pine seedlings appeared after the first year
of the restoration; new objectives were added to the initial one: to
know if organic amendments influence pine growth among planted
vegetation, and if there were competition among planted species,
opportunistic species and pines. Essential soil parameters, plant cover
and diversity and pine growth were measured and statistically processed
with correlation analyses, ANOVA and Detrended Correspondence Analysis.
Six years after restoration organic amendments, applied all over the
plots contributed significantly to explain the differences on the tested
variables. The combined effects of the two substrates and the two
organic amendments effectively enhanced soil properties recovery, but
they also facilitated the establishment and entry of new species in
addition to planted vegetation, driving a differential plant
development. The number of pines, as well as their coverage, depended on
the interaction between the amendment and the substrate: a) only one
amendment favoured the pines and b) the way the amendment works depended
on the substrate. Planted vegetation cover and total plant cover from
amended plots doubled that of control plots. Results indicate the
potential suitability of organic amendments, pine chips mulch and
derived opportunistic species for restoring post-mining areas.